Integral blow-molded, steel reinforced automotive seating structure

ABSTRACT

A method of manufacturing a seat back includes placing a steel support structure within a mold and blow-molding a hollow plastic body onto the steel support structure to form a seat back with the steel support structure integrally supported within the body. The steel support structure may be a hollow, U-shaped steel tube having first and second attachment features at distal ends thereof for attachment to a lower seat structure.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a seating structure and a method of manufacturing a seating structure in which a steel support structure is placed within a mold and a plastic body is blow-molded against the steel support structure to form a seat back in which the steel structure is integrally supported in the body.

[0003] 2. Background Art

[0004] In vehicle interior design, there exists a continuing need to reduce costs, part count and weight associated with vehicle seat assemblies while the vehicle seat assemblies are required to satisfy various design requirements, such as flexibility for improved cargo storage, comfort, safety, etc. In vans, minivans and sport utility vehicles, bench seats or split bench seats are often provided in the second and third row of the vehicle. These seats must be lightweight if they are collapsible or removable. Also, it is generally desirable to provide lightweight seats even if they are not removable. Due to increasing cargo transporting usage of such vehicles, it is important that these seats be designed to withstand significant impact from the rear as a result of forward movement of cargo stored in the rear of the vehicle.

[0005] It is desirable to provide a reinforced, lightweight and low cost seat assembly to satisfy impact requirements and provide the needed functionality while minimizing costs associated with the manufacture and assembly of the seat.

SUMMARY OF THE INVENTION

[0006] The present invention provides a seating apparatus and a method of manufacturing a seating apparatus in which a steel support structure is placed within a mold and a plastic body is blow-molded over the steel support structure to form a seat back wherein the steel support structure is integrally supported in the body.

[0007] The steel support structure is preferably a hollow, U-shaped steel tube having first and second attachment features at distal ends thereof. Alternatively, if the rear impact requirements were minimal, the steel support structure may comprise first and second independent partial frame supports configured for pivotal attachment to a lower seat. Of course, these designs may be tuned to provide the appropriate rear impact support.

[0008] In the preferred embodiment, the hollow, U-shaped steel tube would be swedged into a flat configuration at its distal ends, and the first and second attachment features would comprise holes drilled through the swedged ends. Preferably, the blow-molded plastic body would be a hollow structure with front and rear walls and would include C-shaped portions positioned around the steel support structure to rigidly attach the plastic base to the steel support structure.

[0009] Accordingly, an object of the invention is to provide an improved vehicle seat assembly with reduced manufacturing and assembly costs.

[0010] Another object of the invention is to provide an improved vehicle seat assembly in which a steel support structure is secured to a plastic base in a blow-molding process in which the plastic base is formed.

[0011] The above objects and other objects, features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 shows a perspective view of a seat back assembly in accordance with the present invention;

[0013]FIG. 2 shows a cross-sectional view taken at line 2-2 of FIG. 1;

[0014]FIG. 3 shows a schematic exploded perspective view of an apparatus for blow-molding a seat back in accordance with the embodiment of FIG. 1; and

[0015]FIG. 4 shows a schematic exploded perspective view of an apparatus for blow-molding a seat back in accordance with an alternative embodiment of the invention.

DETAILED DESCRIPTION OF THE BEST MODES FOR CARRYING OUT THE INVENTION

[0016] Referring to FIGS. 1 and 2, a seat back assembly 10 is shown in accordance with the present invention. The seat back assembly shown is provided, for example, for use in a second row split-bench seat in a van. The seat back assembly includes a “60% portion” 12 and a “40% portion” 14. As shown, the 60% portion 12 and 40% portion 14 each include a hollow, U-shaped steel tube 16, 18, respectively. The steel tubes 16, 18 include swedged ends 20, 22, 24, 26 each having an attachment feature, such as a hole 28, 30, 32, 34, respectively. The attachment holes 28, 30, 32, 34 are configured to enable pivotal attachment to a lower seat.

[0017] The U-shaped steel tubes 16, 18 provide considerable impact strength for the seat back portions 12, 14.

[0018] As shown in cross-sectional view in FIG. 2, the plastic body 35 of the 40% portion 14 of the seat back 10 is a hollow, blow-molded structure including front and rear walls 36, 38, respectively. As shown, the plastic body 35 forms a C-shaped portion 40 which is molded over the hollow tube 18 and shrinks onto the tube 18 when cooled to form a secure attachment between the plastic body 35 and the tube 18.

[0019] Returning to FIG. 1, the plastic bodies 33, 35 of the 60% portion 12 and 40% portion 14 of the seat back assembly 10 each include cutout portions 44, 46, 48, 50 through which the distal ends of the U-shaped tubes 16, 18 protrude.

[0020] Referring to FIG. 3, a schematic exploded perspective view of the manufacturing process is shown. The first mold half 56 is supported on a platen 58, and is movable with respect to a second mold half 60 for opening and closing the mold. An extrusion die head 62 is provided above the mold halves 56 and 60 to extrude a thermoplastic parison 64 between the mold halves 56, 60. As illustrated, the steel tubes 16, 18 are inserted into the cavities 52, 54 of the first mold half 56 prior to extrusion of the parison 64. With the hollow parison 64 extended to a position between the mold halves 56, 60, the mold halves 56, 60 are closed together, and a gas, such as air, is blown into the hollow parison to expand the thermoplastic resin of the parison such that the seat backs are formed against the steel tubes 16, 18 within the mold cavities 52, 54 as the mold halves 56, 60 are closed together.

[0021] Prior to the closing of the mold halves 56, 60 together, the steel tubes 16, 18 may be held in the mold cavities 52, 54, respectively, by magnets or by a moving core member which extends to secure the tubes 16, 18 within the mold cavities 52, 54.

[0022] After molding, foam and fabric would be applied to the resulting seat back structures 12, 14.

[0023]FIG. 4 schematically illustrates an alternative embodiment wherein the first and second partial frame supports 70, 72 are inserted into each mold cavity 52, 54 to provide exposed pivotal attachment features 74, 76 on the blow-molded plastic back. The embodiment is useful when lesser rear impact support is necessary, such as in a third row seat.

[0024] Rather than using a hollow steel tube as described herein, a square tube, or other shaped structural steel members could be used. The steel structures are effective in transporting impact energy to the lower seating structure, especially those energies those generated by the headrest and rear intrusion impacts. This invention also addresses the need to reduce part numbers in these assemblies, reduce weight, reduce system costs, and reduce the potential for rattles in comparison with bolted structures.

[0025] While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims. 

What is claimed is:
 1. A method of manufacturing a seat back comprising: placing a hollow steel support structure within a mold; and blow-molding a hollow plastic body onto the steel support structure to form a seat back with the steel support structure integrally supported in the body.
 2. The method of claim 1, wherein said steel support structure comprises a hollow U-shaped steel tube having first and second attachment features at distal ends thereof.
 3. The method of claim 1, wherein said steel support structure comprises first and second partial frame supports configured for pivotal attachment to a lower seat.
 4. The method of claim 1, wherein said body comprises a hollow structure with front and rear walls.
 5. The method of claim 4, wherein said front wall forms C-shaped portions around the steel support structure to rigidly attach the base to the steel support structure.
 6. A seat back comprising: a hollow plastic body blow-molded into a generally rectangular shape; and a steel support structure insert-molded within the body to form the seat back.
 7. The seat back of claim 6, wherein said steel support structure comprises first and second partial frame supports configured for pivotal attachment to a lower seat.
 8. The seat back of claim 7, wherein said distal ends are each swedged into a flat configuration.
 9. The seat back of claim 6, wherein said steel support structure comprises first and second partial frame supports configured for pivotal attachment to a lower seat.
 10. The seat back of claim 6, wherein said body comprises a hollow structure with front and rear walls.
 11. The seat back of claim 10, wherein said front wall forms C-shaped portions around the steel support structure to rigidly attach the base to the steel support structure.
 12. A method of manufacturing a seat back comprising: placing a hollow U-shaped steel tube within a mold, said steel tube having first and second attachment features at distal ends thereof; and blow-molding a plastic body onto the steel support structure to form a seat back with the steel tube integrally supported in the body. 